Polyurethane foam containing synergistic surfactant combinations and process for making same

Abstract

The present invention relates to a composition and process for preparing fine-celled polyurethane foam obtained from frothing a polyurethane foam-forming composition possessing a synergistic combination of silicone surfactants.

Description

FIELD OF INVENTION[0001]The present invention relates to fine-celled polyurethane foam. More particularly, the present invention provides a fine-celled polyurethane foam obtained from mechanically frothing a polyurethane foam-forming composition possessing a synergistic combination of silicone surfactants.BACKGROUND OF THE INVENTION[0002]Mechanically frothed foams have been limited in density reduction in part due to limitations of current surfactant technology used for mechanically frothed foams. Typically the surfactants used for the mechanically frothed foam processes are polydimethylsiloxane / polyether repeating block or (AB)n-type copolymer. For example, hydrolyzable (AB)n surfactants are disclosed in U.S. Pat. No. 3,947,386 and non-hydrolyzable (AB)n surfactants are disclosed in U.S. Pat. No. 3,957,842, both for use in the mechanical froth foam process. The use of either hydrolyzable or non-hydrolyzable (AB)n surfactants in making foam articles including carpet backing is descr...

AI Technical Summary

Benefits of technology

[0024]The present invention provides a fine-celled polyurethane foam obtained from frothing a polyurethane foam-forming composition having low density imparted from a synergistic combination of polysiloxane / polyoxyalkylene (AB)n-type and polysiloxane-polyoxyalkylene pendant-type surfactants. The produced foam may be more cost efficient due to being lighter in weight because of its decreased density. The process can be used with or without chemical blowing assistance, e.g., from the water / isocyanate reaction or from auxiliary blowing agents.

Problems solved by technology

Mechanically frothed foams have been limited in density reduction in part due to limitations of current surfactant technology used for mechanically frothed foams.

One attempt to lower foam density is by using chemical blowing from the reaction of water with isocyanate as described in U.S. Pat. Nos. 6,790,872 and 6,372,810, however, these processes are limited in density reduction in part to the physical limitations of the current surfactant technology.

However, the surfactants used in the disclosed process do not provide for low froth density when compared to surfactants of the (AB)n-type and when used in oven cured conditions have associated foam stabilizing problems which results in higher final foam density.